Patellofemoral Update focuses on the causes, prevention and treatment of patellofemoral disorders. The blog is sponsored by The Patellofemoral Foundation whose mission is to improve the care of individuals with anterior knee pain through targeted education and research. The Patellofemoral Foundation offers additional online education resources on its website.

Is there a role for medial-sided repair in patellar instability?

Historically, combinations of proximal and distal realignment procedures have been used to address patellar instability.

The proximal realignment procedures include medial retinacular repair, medial imbrication, VMO advancement, medial patellofemoral ligament (MPFL) repair or medial capsular reefing, with or without lateral retinacular release. Although several level 4 case series have shown satisfactory results with these proximal realignment procedures, there are at least four level 1 studies which have failed to show a difference between these medial-sided repairs and nonoperative treatment.

MPFL reconstruction

If one had to interpret the results of these level 1 studies, then most patients with medial-sided repair procedures would have done well even without surgery. Although the rationale of medial-sided repair is to repair the torn structures or tighten the stretched tissues, the best available evidence shows these tissues either were competent to start with or that they remained incompetent even after repair.

 

Shital Parikh

MPFL reconstruction adds tissue to the medial side. When MPFL reconstruction was compared to nonoperative treatment, Bitar and colleagues found MFPL reconstruction to be more effective in patellar stabilization. Our study, which compared 20 consecutive MPFL repairs with 20 consecutive MPFL reconstructions in patients with recurrent patellar instability at minimum 2-year follow-up, showed seven recurrent dislocations after MPFL repair and no recurrent dislocations after MPFL reconstruction. Based on review of literature and our experience, we have abandoned medial-sided repair and favor MPFL reconstruction as primary procedure of choice for patellar stabilization.

Patient-related outcomes

Medial-sided repair may have a place in treatment of patellar instability. In the absence of high-level evidence supporting the efficacy of medial-sided repair and due to the difficulty in identifying the optimal patients for repair, the role of medial-sided repair to address patellar instability remains negligible and debatable. On the other hand, MPFL reconstruction may be overkill and has its own set of complications, but it has provided better clinical and patient-related outcomes than any other proximal realignment procedure for patellar stabilization.

References:

Bitar AC. Am J Sports Med. 2012;doi:10.1177/0363546511423742.

Christiansen SE. Arthroscopy. 2008;doi:10.1016/j.arthro.2008.03.012.

May M. Paper #484. Presented at: American Academy of Orthopaedic Surgeons Annual Meeting; San Diego; Feb. 15-19, 2011.

Nikku R. Operative treatment of primary patellar dislocation does not improve medium-term outcome: A 7-year follow-up report and risk analysis of 127 randomized patients. Acta Orthop. 2005;76(5):699-704.

Palmu S. J Bone Joint Surg Am. 2008;doi:10.2106/JBJS.G.00072.

Sillanpaa PJ. Am J Sports Med. 2008;doi:10.1177/0363546508322894.

  • Shital N. Parikh, MD, FACS, is an associate professor of orthopedic surgery, Cincinnati Children’s Hospital Medical Center, University of Cincinnati School of Medicine, Cincinnati. He can be emailed at:Shital.Parikh@cchmc.org.
  • Disclosure: Parikh has no relevant financial disclosures.

 

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